Abstract:

The combined lines having both phKL and Ph2-deficiency were obtained in the genetic back-ground of common wheat (Triticum aestivum L.) landrace. These lines had normal fertility. In the wheat combined lines　×Aegilops variabilis (or rye), a significant increase in the chiasmata of homoeologous pairing was shown by the phKL+Ph2- plants with respect to their phKL+Ph2 sibs, which indicates that Ph2-deficiency and phKL showed an additive effect on promoting pairing. The effects were shown in the increment of rod bivalents, ring bivalents and trivalents and reduction of univalents. Of which, reduction of univalents was mainly due to the increment of rod bivalents. The combined lines are probably more desir-able materials for alien gene transferring than phKL or Ph2- lines alone. In comparison with that of ph1b　Ae. variabilis (or rye), phKL+Ph2-×Ae. variabilis (or rye) show higher (or similar) numbers of rod bivalents, while the total chromosome pairing level significantly reduced that ascribed to the decrement in ring bivalents and multivalents. These results probably indicate the different genetic mechanism for Ph1 and Ph2 or phKL on controlling homoeologous pairing.

p h K L 基因和P h 2 基因缺失重组体的创制及其与小麦外源物种
杂种的染色体减数分裂观察
刘登才  郑有良 颜泽洪 周永红 魏育明 兰秀锦
（四川农业大学小麦研究所，都江堰市 611830)

摘要: 以小麦(Triticum aestivum L.)双端体3DL 为细胞学标记,用具有phKL 基因的小麦地方品种“开县罗汉
麦”为受体连续回交，将促进小麦外源部分同源染色体配对的phKL 基因和Ph2 基因缺失重组在一起获得了重组体phKL + Ph2 -。这种重组体有正常的育性。与只有phKL 基因的小麦材料相比，重组体与外源物种Aegilopsvariabilis Eig.或黑麦(Secale cereale L.)杂种的部分同源染色体配对水平显著增加，表明Ph2 基因的缺失体与phKL 基因可能存在加性效应。部分同源染色体配对水平的增加表现在棒状二价体、环状二价体和三价体的数量变多而单价体数量减少。单价体的减少主要是由于棒状二价体的增加所造成的。在小麦外源遗传转移中,运用重组体phKL+Ph2 - 可能比单纯应用Ph2 缺失或phKL 基因材料更理想。当与具有ph1b 基因的材料比较时发现，重组体phKL+Ph2 ^- 与Ae. variabilis(或黑麦)杂种的部分同源染色体配对水平显著降低，这主要是由环状二价体和多价体的减少造成的，但是棒状二价体数量表现增加(与Ae. variabilis 杂种)或达到类似水平(与黑麦杂种)，这一有趣的发现从表现型上证明了Ph1 基因与Ph2 或phKL 基因在诱导部分同源染色体配对时的遗传作用机制存在差异。
关键词： 小麦; 同源染色体配对; Ph 基因; 中期Ⅰ配对; 种间杂种
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